1. Field of the Invention
The present invention relates to home appliances and more specifically, to a lighted appliance knob for indicating the operative condition of an appliance. The lighted knob may be installed on any appliance which has a knob for turning on the appliance, whether the appliance operates on electricity, or whether the appliance has a mechanical valve, such as a gas powered appliance.
2. Description of the Related Art
Lighted knobs and methods for sensing and indicating the operative condition of an appliance are well represented in the prior art. Sensing the xe2x80x9conxe2x80x9d state of an appliance is a highly desired feature in an appliance, especially in one powered by electricity or gas.
The sensing of the operative state of an appliance and the signaling of that active state to a user are known to those skilled in the art. U.S. Pat. No. 5,939,992, issued to Devries et al., U.S. Pat. No. 4,255,669, issued to Naugle, U.S. Pat. No. 4,446,455, issued to Nashawaty, U.S. Pat. No. 5,467,077, issued to Wunderlich et al. and U.S. Pat. No. 5,608,378, issued to McLean et al., are but a few of the patents disclosing sensor circuits signaling to an external indicating device the operative state of an electrical appliance. The aforementioned devices all suffer from the requirement of relatively complex electronic circuitry mounted on a circuit board located within the appliance, and depend upon the power source of the appliance to energize the sensing circuitry.
Lighted appliance knobs have served both for illumination in low light situations and for indicating the operative condition of the appliance. U.S. Pat. No. 3,864,561, issued to Spira et al. in 1975, relates to a lamp in a dimmer switch powered by voltage source that is itself controlled by the switch. U.S. Pat. No. 5,093,764, issued to Hasegawa et al. in 1992, discloses a coaxial switch illuminated by a light source on the back of the panel surface on which the switch is mounted for indicating the xe2x80x9conxe2x80x9d position of an air conditioning or similar system. U.S. Pat. No. 5,335,148, issued to Tominaga, includes an illuminated knob, the rotary shaft of a variable resistor, a switch and a light-emitting diode. Taniuchi discloses in U.S. Pat. No. 5,901,836 a lighted knob switch combination which receives power from the appliance and consists of springs and contacts which close when the knob is rotated thus providing current to a small lamp or light emitting diode. U.S. patent application Ser. No. 2002/0075668 proposes to illuminate the adjusting knob by means of a light guide and light-emitting diodes on a printed-circuit board mounted to a dividing wall between the knob and the appliance. These devices suffer from a complexity of design, require the appliance to provide the power to light the lamp, or have the lamp in the panel surface behind the knob as opposed to being integrated within the knob.
None of the above inventions and patents, taken either singly or in combination, is seen to describe a self-contained lighted knob which serves to indicate the operative state of an appliance as claimed in the instant invention. Thus a lighted appliance knob solving the aforementioned problems is desired.
The present invention is a safety device in the form of a lighted knob adapted for indicating the operative condition of an appliance. Oftentimes, people, especially the elderly and children of all ages, forget to turn off appliances after use. This has been the cause of many electrical fires and gas explosions. To aid in visually identifying when an appliance is active, the present invention includes a lighted knob and self-contained circuitry which operates independent of the energy source supplying the appliance. The lighted knob has a light source mounted on the outer surface of the knob, a tilt or attitude sensing electrical switch, and a battery compartment. The knob is so designed that when it is mounted vertically on an appliance, any axial rotation of the knob away from the xe2x80x9coffxe2x80x9d position will complete an electric circuit illuminating the light, signaling the operating state of the appliance to the user. The light goes off when the knob is turned to the xe2x80x9coffxe2x80x9d position, indicating the safe and inoperative condition of the appliance. The knob requires no activation other than installation of a battery. All integral parts are sealed within the knob housing for reliability and safety. The lighted knob can be constructed to replace virtually any style appliance knob, or may be offered as part of original manufactured equipment.
Accordingly, it is a principal object of the invention to provide a safety device for indicating the xe2x80x9conxe2x80x9d condition of an appliance.
It is another object of the invention to provide a method of using a lighted appliance knob for indicating the active condition of an appliance.
It is a further object of the invention to provide a lighted appliance knob with all required components contained within the knob and which is powered independent of the source of power of the appliance.
Still another object of the invention is to provide a lighted appliance knob which may be installed either as original equipment at the time of manufacture or as an aftermarket modification.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable, environmentally safe and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.